“Most of what I know about myself, I have learned from playing Schumann.”

This brief sentence contains an entire world in which music, emotion, and the selves of performer and composer coincide. The words were written by Jonathan Biss, 32,
who in addition to being a superb pianist is also an eloquent and insightful music writer. Last fall he published a Kindle Single called “A Pianist Under the Influence,” a meditation not just on Schumann’s magnificently elusive music but on the uncanny pull it has exerted on Biss.

The essay is one part of Biss’s season-long project called “Schumann: Under the Influence,” dedicated to exploring the music that turned Robert Schumann (1810-56) into the composer that he was and the influence he has exerted on composers who followed, from then to the present day. The project encompasses a series of concerts, including two at Jordan Hall. The first is Friday, when Biss plays Schumann’s “Fantasiestücke” and “Davidsbündlertänze” alongside music of Janacek and Berg. Biss returns in April with the Elias String Quartet, with whom he recently recorded the Schumann and Dvorak piano quintets.

This is no dry exercise in historical scrutiny. For Biss, playing Schumann has always provided a guide to realms of the soul that are otherwise inaccessible.

“With so much of the other great music that’s important to me, I am in awe,” Biss says in a phone interview from his New York home. “There’s no question that I hear pretty much everything that Beethoven wrote and I have this reaction: It’s not really possible that a human being could have created that.”

With Schumann, though, there’s a different connection established, such that the music “manages to say for me things which I know about myself but which I would never be able to articulate. It knows things about vulnerability and about what it means to be alone with yourself and about what it means to feel loved, with all its implications — which are very, very profound and very, very personal.”

Personal, private, secretive — those words crop up again and again while talking about Schumann’s music. “I think the privacy of the experience is really an essential part of the DNA of this music,” Biss says. Again, Beethoven provides a convenient foil. “You feel with Beethoven that he wants — he needs — the world to listen to him — in as large a group as possible, probably. But I always feel that Schumann is addressing someone on a one-to-one basis.”

There’s almost a halting quality to some of Schumann’s most important works, Biss continues, a sense that things can be said only with great difficulty. “Fluency is not one of the values of this music. There are moments in all his pieces where you have this feeling that the notes don’t come easily, that they rise to the surface with great effort. And I think that’s as private a form of musical expression as I can imagine.”

Biss thinks that that hesitant, ambivalent tone is one reason Schumann has been subject to a certain level of condescension. It’s true that even today you hear criticism: that his grasp of structure was faulty, that he couldn’t orchestrate, that — perhaps most damning —
he stands at the margins of music history, outside its main currents. Had Schumann never existed, this view goes, we’d miss out on some beautiful works, but the course of music history would be unchanged.

Arguing against this point is the polemical thrust of “Schumann: Under the Influence.”

“I think in his own subtle and personal way, Schumann was a tremendous influence and inspiration to composers who came after, both immediately and up to the present day,” Biss says. “Let’s see the music that was essential to him and, more important for me, take a look at the music that comes over the space of 150 years which would not have been possible without him.”

Among that music is a new piano quintet by Timothy Andres, 27,
a New York-based composer (on the April Jordan Hall program). Biss said that since the other composers in his Schumann project are European, he liked the idea of a contemporary piece from an American.

The premise of the Andres piece is a hypothetical: What if Schumann had decided to write his piano quintet as a series of miniatures, rather than as the full-fledged movement he composed? Andres takes a central motif — an obscure Schumann reference — and fashions around it five short movements, played without pause. “And he’s come up with something that’s very beautiful and totally original, and yet has Schumann in its DNA.”

One of the most poignant sections of Biss’s Kindle book describes how he learned, just before recording the “Davidsbündlertänze,” that a friend had taken his own life. Hearing the news, Biss sat at the piano and played through its 18 brief movements.

“The Davidsbündlertänze,” he wrote, “managed to say all the things I wanted to, but could not.”

Which brings up the question of how one can take this intensely private experience, art that reaches deep into the self, and share it with a roomful of people. In the face of such deep poignancy, it’s worth wondering whether the concert-giving experience isn’t something too public, too exposed, for this fragile art.

“It’s definitely a struggle,” Biss admits. “I’ve played this recital program now four times in a row, and it would not be an exaggeration to say that I feel shattered afterwards. It’s honestly terrifying — I think one should be willing to say that.

“But then when I think about it for a little while,” he goes on, “I’m vividly conscious of what an amazing thing it is, to get to share that with people. It’s very, very difficult, and it does not necessarily feel healthy. But as a thing in your life that you feel that strongly for and that is so intimately bound up with who you are, and to be able to share it with people and know that some of them might have a reaction that’s as strong — that’s an amazing thing. It really is.”